DOCSLIB.ORG

The Present Role and New Potentials of Anaerobic Fungi in Ruminant Nutrition

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Present Role and New Potentials of Anaerobic Fungi in Ruminant Nutrition Journal of Fungi Review The Present Role and New Potentials of Anaerobic Fungi in Ruminant Nutrition Thomas Hartinger * and Qendrim Zebeli Institute of Animal Nutrition and Functional Plant Compounds, University of Veterinary Medicine Vienna, 1210 Vienna, Austria; [email protected] * Correspondence: [email protected] Abstract: The ruminal microbiota allows ruminants to utilize fibrous feeds and is in the limelight of ruminant nutrition research for many years. However, the overwhelming majority of investigations have focused on bacteria, whereas anaerobic fungi (AF) have been widely neglected by ruminant nutritionists. Anaerobic fungi are not only crucial fiber degraders but also important nutrient sources for the host. This review summarizes the current findings on AF and, most importantly, discusses their new application potentials in modern ruminant nutrition. Available data suggest AF can be applied as direct-fed microbials to enhance ruminal fiber degradation, which is indeed of interest for high-yielding dairy cows that often show depressed ruminal fibrolysis in response to high-grain feeding. Moreover, these microorganisms have relevance for the nutrient supply and reduction of methane emissions. However, to reach AF-related improvements in ruminal fiber breakdown and animal performance, obstacles in large-scale AF cultivation and applicable administration options need to be overcome. At feedstuff level, silage production may benefit from the application of fungal enzymes that cleave lignocellulosic structures and consequently enable higher energy exploitation from forages in the rumen. Concluding, AF hold several potentials in improving ruminant feeding and future research efforts are called for to harness these potentials. Citation: Hartinger, T.; Zebeli, Q. Keywords: additive; anaerobic digestion; cattle; enzyme; anaerobic fungi; herbivore; Neocalli- The Present Role and New Potentials mastigomycota; rumen; silage of Anaerobic Fungi in Ruminant Nutrition. J. Fungi 2021, 7, 200. https://doi.org/10.3390/jof7030200 1. Introduction Academic Editor: Laurent Dufossé The metabolic processes in the rumen are of crucial importance in ruminant nutrition and decisively influence the host supply with energy and valuable nutrients. Hence, the Received: 23 February 2021 rumen microbiota is of key interest in this interdisciplinary research field. Although it is Accepted: 5 March 2021 Published: 10 March 2021 common consensus that the ruminal ecosystem comprises various distinct microbial groups, i.e., bacteria, protozoa, archaea, fungi, and viruses [1], the myriad of microbiota-related Publisher’s Note: MDPI stays neutral studies in ruminant nutrition, however, are predominantly focusing on bacteria. Whilst with regard to jurisdictional claims in also the domains archaea and protozoa gained attention in terms of methane emissions or published maps and institutional affil- intra-ruminal nitrogen (N) recycling [2,3], AF (phylum Neocallimastigomycota) have yet iations. been widely neglected in the wider ruminant nutrition research. However, these obligate anaerobes are commensals along the gastrointestinal tract of ruminants, being mainly present in the forestomach [4], and truly vital for sufficient fiber degradation by means of expressing various carbohydrate-active enzymes (CAZymes), which can be organized in cellulosomes, as well as physically penetrating plant material via rhizoidal systems [5–7]. Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. In fact, AF and their capabilities are highly recognized among microbiologists and This article is an open access article comprehensive scientific efforts have been made regarding their taxonomy, lifecycle, and distributed under the terms and metabolic characterization, which recently was excellently summarized by Hess et al. [5]. conditions of the Creative Commons Notwithstanding, AF appear to be equally relevant to ruminant nutritionists, who continu- Attribution (CC BY) license (https:// ally seek for strategies to optimize ruminal fiber degradation, a process in which AF are creativecommons.org/licenses/by/ indeed substantially involved [5,7]. Likewise, this microbial clade seems significant for 4.0/). further aspects related to modern livestock feeding. Therefore, by portraying the current J. Fungi 2021, 7, 200. https://doi.org/10.3390/jof7030200 https://www.mdpi.com/journal/jof J. Fungi 2021, 7, 200 2 of 15 perception of AF in ruminant nutrition and outlining their potential in this research field, this review extends the perspective on AF and aims to stimulate scientific discourse on their relevance in modern ruminant feeding as well as sensitize ruminant scientists for these hidden champions in the gut. Since Hess et al. [5] provide an extensive status quo on AF live cycle and taxonomy, the present review will not cover those aspects, albeit a new fungal taxon has again been isolated in the meantime [8]. Similarly, the reader is further encouraged to consult the article of Vinzelj et al. [9] for general basics on AF as well as thorough considerations about their cultivation. 2. Current Perception of Anaerobic Fungi in Ruminant Nutrition In terms of microbiota-related research, the field of ruminant nutrition is doing tremen- dous efforts to understand how the gut microbiota can be shaped by feeding to optimize rumen fermentation, nutrient provision to the host, as well as gut health and ultimately prevent diseases along with improving animal performance. Thereby, major focus is placed on the rumen, i.e., the gut segment that harbors a highly complex microbial community enabling the energetic utilization of structural carbohydrates as well as providing key nutrients, such as protein and vitamins, to the host animal [1,10]. In the last decades, the hindgut microbiota also became a subject of increasing interest for ruminant nutritionists, particularly in relation to high-grain feeding and associated microbial dysbiosis [11]. With few exceptions and irrespective of gut segment investigated, bacteria represent the target domain in nutritional studies with ruminants, as exemplified by the survey of Hender- son et al. [12], who investigated the influence of diet on the ruminal microbiota composition on a global scale, exploring bacteria, archaea, and protozoa. Anaerobic fungi, however, have not been included in this specific study and although AF have been introduced as potent fiber degraders in relevant ruminant nutrition journals very early [7], these microorganisms remain mostly unconsidered so far [12–16]. Therefore, including AF in future ruminant nutrition studies should be the logical outcome, as otherwise, a holistic capture of the rumen microbiota and its implications on nutrition seem hardly feasible. As a complemental note, the authors like to direct additional awareness to AF in the hindgut, which may be more vital for equines at first sight. However, a considerable number of active AF is present in the ruminant’s lower gut [4,17] and since concentrate-rich feeding can shift substrate degradation from the rumen to the hindgut [18], it would be irrational to disregard the fungal population in this part of the gastrointestinal tract. Interestingly, the rumen simulation technique of Czerkawski and Breckenridge [19] constitutes an in vitro system suitable for long-term incubation that is widespread in rumi- nant nutrition and may be an excellent option for studying rumen AF in all its aspects. In fact, this system has already been used in the past to explore these microorganisms [20–22] and due to its continuous flow of the liquid fraction was actually deemed a better approach for investigating rumen AF than batch cultures [20]. 2.1. Ruminal Fiber Degradation It is well established that AF contribute significantly to ruminal fiber degradation by attacking plant cell walls in two ways, i.e., enzymatically, and physically [5–7]. Remarkably, recent research showed the affinity of fungal CAZymes for recalcitrant fiber [23], which may explain the particular significance of AF when feeding low-quality forage to ruminants. The authors, however, will not review explicitly on the enzymatic repertoire of AF as fungal CAZymes and the associated cellulosomes have been the subject of earlier reviews [5,24] and a current list of all fungal CAZymes discovered so far is provided by Hess et al. [5]. The synergistic activity of CAZymes, either individually or organized as cellulosomes, and mechanical penetration of plant cell wall by fungal hyphae results in an enhanced cleavage of fibrous structures by AF [5], which will also increase the access for other rumen cellulolytics and likely also proteolytics [2]. Indeed, cell wall degradation by AF can be higher than by bacteria under certain in vitro conditions [25,26] but quantifying the exact fungal contribution to fiber breakdown in the rumen is difficult. However, J. Fungi 2021, 7, 200 3 of 15 several in vitro and in vivo studies demonstrated the association between AF and an improved fiber degradability [25–28], which is also suggested by recent in vitro data from Ma et al. [26]. These authors investigated the impact of co-culturing methanogens with either AF or bacteria on in vitro degradation of rice and wheat straw, observing higher dry matter and fiber degradation in the presence of AF, the extent of which was similar to lignocellulose breakdown by whole ruminal content. Interestingly, acetate production was even higher in the co-occurrence of AF and methanogens than for whole ruminal content or methanogens and bacteria
Load more

Recommended publications
  • Ruminal Protection and Intestinal Availability of Rumen-Protected Methionine and Lysine in Lactating Dairy Cows
    Utah State University DigitalCommons@USU All Graduate Theses and Dissertations Graduate Studies 5-2019 Ruminal Protection and Intestinal Availability of Rumen-Protected Methionine and Lysine in Lactating Dairy Cows Sara Menchu Utah State University Follow this and additional works at: https://digitalcommons.usu.edu/etd Part of the Dairy Science Commons Recommended Citation Menchu, Sara, "Ruminal Protection and Intestinal Availability of Rumen-Protected Methionine and Lysine in Lactating Dairy Cows" (2019). All Graduate Theses and Dissertations. 7451. https://digitalcommons.usu.edu/etd/7451 This Thesis is brought to you for free and open access by the Graduate Studies at DigitalCommons@USU. It has been accepted for inclusion in All Graduate Theses and Dissertations by an authorized administrator of DigitalCommons@USU. For more information, please contact [email protected]. RUMINAL PROTECTION AND INTESTINAL AVAILABILITY OF RUMEN- PROTECTED METHIONINE AND LYSINE IN LACTATING DAIRY COWS by Sara Menchu A thesis submitted in partial fulfillment of requirements for the degree of MASTER OF SCIENCE in Animal, Dairy, and Veterinary Sciences Approved: Jeffery O. Hall, D.V.M., Ph.D. Jong-Su Eun, Ph.D. Major Professor Committee Member Kerry A. Rood, M.S., D.V.M., M.P.H. Richard S. Inouye, Ph.D. Committee Member Vice Provost for Graduate Studies UTAH STATE UNIVERSITY Logan, Utah 2019 Copyright © Sara Menchu 2019 All Rights Reserved iii ABSTRACT Ruminal Protection and Intestinal Availability of Rumen-Protected Methionine and Lysine in Lactating Dairy Cows by Sara S. Menchu, Master of Science Utah State University, 2019 Major Professor: Dr. Jeffery O. Hall Department: Animal, Dairy, and Veterinary Sciences Rumen protected Methionine (MET) and Lysine (LYS) are critical for milk protein synthesis in dairy cows.
    [Show full text]
  • Altering the Gut Microbiome of Cattle: Considerations of Host-Microbiome Interactions for Persistent Microbiome Manipulation
    Microbial Ecology https://doi.org/10.1007/s00248-018-1234-9 HOST MICROBE INTERACTIONS Altering the Gut Microbiome of Cattle: Considerations of Host-Microbiome Interactions for Persistent Microbiome Manipulation Brooke A. Clemmons1 & Brynn H. Voy1 & Phillip R. Myer1 Received: 18 September 2017 /Accepted: 16 July 2018 # Springer Science+Business Media, LLC, part of Springer Nature 2018 Abstract The beef cattle industry represents a significant portion of the USA’s agricultural sect, with beef cattle accounting for the most red meat consumed in the USA. Feed represents the largest input cost in the beef industry, accounting for approximately 70% of total input cost. Given that, novel methods need to be employed to optimize feed efficiency in cattle to reduce monetary cost as well as environmental cost associated with livestock industries, such as methane production and nitrogen release into the environment. The rumen microbiome contributes to feed efficiency by breaking down low-quality feedstuffs into energy substrates that can subsequently be utilized by the host animal. Attempts to manipulate the rumen microbiome have been met with mixed success, though persistent changes have not yet been achieved beyond changing diet. Recent technological advances have made analyzing host-wide effects of the rumen microbiome possible, as well as provided finer resolution of those effects. This manuscript reviews contributing factors to the rumen microbiome establishment or re-establishment following rumen microbiome perturbation, as well as host-microbiome interactions that may be responsible for possible host specificity of the rumen microbiome. Understanding and accounting for the variety of factors contributing to rumen microbiome establishment or re-establishment in cattle will ultimately lead to identification of biomarkers of feed efficiency that will result in improved selection criteria, as well as aid to determine methods for persistent microbiome manipulation to optimize production phenotypes.
    [Show full text]
  • Biosynthesis of Conjugated Linoleic Acid and Its Incorporation Into Ruminant's Products**
    306 Biosynthesis of Conjugated Linoleic Acid and Its Incorporation into Ruminant’s Products** Man K. Song* and John J. Kennelly1 Department of Animal Science, Chungbuk National University, Cheongju 361-763, Korea ABSTRACT : Bio-hydrogenation of C18-unsaturated fatty acids released from the hydrolysis of dietary lipids in the rumen, in general, occurs rapidly but the range of hydrogenation is quite large, depending on the degree of unsaturation of fatty acids, the configuration of unsaturated fatty acids, microbial type and the experimental condition. Conjugated linoleic acid (CLA) is incompletely hydrogenated products by rumen microorganisms in ruminant animals. It has been shown to have numerous potential benefits for human health and the richest dietary sources of CLA are bovine milk and milk products. The cis-9, trans-11 is the predominant CLA isomer in bovine products and other isomers can be formed with double bonds in positions 8/10, 10/12, or 11/13. The term CLA refers to this whole group of 18 carbon conjugated fatty acids. Alpha-linolenic acid goes through a similar bio-hydrogenation process producing trans-11 C18:1 and C18:0, but may not appear to produce CLA as an intermediate. Although the CLA has been mostly derived from the dietary C18:2 alternative pathway may be existed due to the extreme microbial diversity in the reticulo-rumen. Regardless of the origin of CLA, manipulation of the bio-hydrogenation process remains the key to increasing CLA in milk and beef by dietary means, by increasing rumen production of CLA. Although the effect of oil supplementation on changes in fatty acid composition in milk seems to be clear its effect on beef is still controversial.
    [Show full text]
  • Amino Acids in Rumen Escape Protein COOPERATIVE EXTENSION
    UC COOPERATIVE EXTENSION CE UNIVERSITY OF CALIFORNIA, DAVIS Amino Acids in Rumen Escape Protein 3. Plant and Non-Plant Source Protein Meals P.H. Robinson Cooperative Extension Specialist University of California, Davis, CA 95616-8521 Dairy cattle require dietary nitrogen and proteins to meet the requirements of their ruminal populations of microorganisms. If ruminal microorganisms, particularly bacteria, become nitrogen deficient then their growth and fermentative activity can be restricted leading to reduced digestion of structural carbohydrates and declining levels of feed intake. These microorganisms, which die and wash out of the rumen to the small intestine, provide a substantial proportion of the protein which is absorbed from the small intestine of the animal to meet the animal’s metabolic requirements for amino acids, which are the building blocks of proteins. However, with the exception of the lowest producing bovines, the microbial contribution alone is seldom sufficient to meet these metabolic requirements making enhancement of intestinally delivered supplies of protein from dietary feed sources critical if the animal is to reach its genetic potential for productivity. Plant and non-plant source protein meals comprise a portion of most successful rations for lactating dairy cows. These feedstuffs are typically added to the diet primarily to contribute protein, often intestinally absorbable protein, but also contribute variable quantities of non-structural carbohydrates that are available to be fermented by microbes in the rumen. Protein meals containing between 40 and 90% crude protein, of which 20 to 70% escapes the rumen undegraded, that is fed at 5% to 15% of total dry matter intake to high producing dairy cows will supply between 500 and 1000 g of intestinally absorbable amino acids.
    [Show full text]
  • Longitudinal Evaluation of Fecal Microbiota Transplantation for Ameliorating Calf Diarrhea and Improving Growth Performance
    ARTICLE https://doi.org/10.1038/s41467-020-20389-5 OPEN Longitudinal evaluation of fecal microbiota transplantation for ameliorating calf diarrhea and improving growth performance Hyun Sik Kim1,5, Tae Woong Whon1,3,5, Hojun Sung1, Yun-Seok Jeong1, Eun Sung Jung 2, Na-Ri Shin1,4, ✉ Dong-Wook Hyun1, Pil Soo Kim1, June-Young Lee1, Choong Hwan Lee2 & Jin-Woo Bae 1 1234567890():,; Calf diarrhea is associated with enteric infections, and also provokes the overuse of anti- biotics. Therefore, proper treatment of diarrhea represents a therapeutic challenge in live- stock production and public health concerns. Here, we describe the ability of a fecal microbiota transplantation (FMT), to ameliorate diarrhea and restore gut microbial compo- sition in 57 growing calves. We conduct multi-omics analysis of 450 longitudinally collected fecal samples and find that FMT-induced alterations in the gut microbiota (an increase in the family Porphyromonadaceae) and metabolomic profile (a reduction in fecal amino acid con- centration) strongly correlate with the remission of diarrhea. During the continuous follow-up study over 24 months, we find that FMT improves the growth performance of the cattle. This first FMT trial in ruminants suggest that FMT is capable of ameliorating diarrhea in pre- weaning calves with alterations in their gut microbiota, and that FMT may have a potential role in the improvement of growth performance. 1 Department of Life and Nanopharmaceutical Sciences and Department of Biology, Kyung Hee University, Seoul 02447, Republic of Korea. 2 Department of Bioscience and Biotechnology, Konkuk University, Seoul 05029, Republic of Korea. 3Present address: Microbiology and Functionality Research Group, World Institute of Kimchi, Gwangju 61755, Republic of Korea.
    [Show full text]
  • Ruminant Animal? Many Different Species of Ruminant Animals Are Found Around the World
    What is a Ruminant Animal? Many different species of ruminant animals are found around the world. Ruminants include cattle, sheep, goats, buffalo, deer, elk, giraffes and camels. These animals all have a digestive system that is uniquely different from our own. Instead of one compartment to the stomach they have four. Of the four compartments the rumen is the largest section and the main digestive centre. The rumen is filled with billions of tiny microorganisms that are able to break down grass and other coarse vegetation that animals with one stomach (including humans, chickens and pigs) cannot digest. Ruminant animals do not completely chew the grass or vegetation they eat. The partially chewed grass goes into the large rumen where it is stored and broken down into balls of “cud”. When the animal has eaten its fill it will rest and “chew its cud”. The cud is then swallowed once again where it will pass into the next three compartments—the reticulum, the omasum and the true stomach, the abomasum. Dairy calves have a four-part stomach when they are born. However, they function primarily as a monogastric (simple-stomached) animal during the first part of their lives. At birth the first three compartments of a calf’s stomach—rumen, reticulum, and omasum—are inactive and undeveloped. As the calf grows and begins to eat a variety of feeds, its stomach compartments also begin to grow and change. The abomasum constitutes nearly 60 percent of the young calf’s stomach, decreasing to about 8 percent in the mature cow. The rumen comprises about 25 percent of the young calf’s stomach, increasing to 80 percent in the mature cow.
    [Show full text]
  • Methane Production in Ruminant Animals: Implication for Their Impact on Climate Change
    Concepts of Dairy & Veterinary Sciences DOI: ISSN: 2637-4749 10.32474/CDVS.2019.02.000142Review Article Methane Production in Ruminant Animals: Implication for Their Impact on Climate Change Mebrate Getabalew1, Tewodros Alemneh2* and Dawit Akeberegn3 1College of Agricultural and Natural Resource Science, Department of Animal Science, Debre Berhan University, Ethiopia 2Woreta Town Office of Agriculture and Environmental Protection, South Gondar Zone, Amhara Regional State, Ethiopia 3Debre Berhan City Municipality Office, Meat Inspection and Hygiene, Amhara Regional State, Ethiopia *Corresponding author: Tewodros Alemneh, Woreta Town Office of Agriculture and Environmental Protection, South Gondar Zone, Amhara Regional State, Ethiopia Received: Published: January 03, 2019 April 04, 2019 Abstract Agriculture accounts for about 47%-56% of the total anthropogenic methane (CH4) emission. It is known that from the agricultural sector, ruminant livestock (dairy, beef, goats, and sheep) substantially contributes to the increase in CH4 production through continuous natural rumen fermentation process. Methane emission is now the second contributor to global warming, which it has 23 times more influence than that of carbon dioxide (CO2). Many factors affect the amount of ruminant CH4 production, including level of feed intake, type and quality of feeds, energy consumption, animal size, growth rate, level of production, and environmental temperature. Methane also produced from manure of animals depending on the physical form of the faeces, the amount of digestible material, the climate, and the time they remained intact. The major part of methanogenesis in ruminants occurs in the large fermentative chamber, which is rumen. Ruminal digestion of feed by microorganisms, under anaerobic conditions, results in the production of acetate, propionate and butyrate (volatile fatty acids) which are used by the animal as energy source, and production of ruminal gases such as carbon dioxide (CO2) and CH4, which eliminated through eructation.
    [Show full text]
  • Characterization of Anaerobic Rumen Fungal Community Composition in Yak, Tibetan Sheep and Small Tail Han Sheep Grazing on the Qinghai-Tibetan Plateau
    animals Article Characterization of Anaerobic Rumen Fungal Community Composition in Yak, Tibetan Sheep and Small Tail Han Sheep Grazing on the Qinghai-Tibetan Plateau Wei Guo 1, Weiwei Wang 1, Sisi Bi 2, Ruijun Long 2, Farman Ullah 3, Muhammad Shafiq 4 , Mi Zhou 5,* and Ying Zhang 6,* 1 State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China; [email protected] (W.G.); [email protected] (W.W.) 2 School of Life Sciences, Lanzhou University, Lanzhou 730020, China; [email protected] (S.B.); [email protected] (R.L.) 3 Department of Animal Breeding and Genetics, Lasbela University of Agriculture Water and Marine Sciences, Uthal 90150, Pakistan; [email protected] 4 College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; drshafi[email protected] 5 Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2P5, Canada 6 School of Public Health, Lanzhou University, Lanzhou 730020, China * Correspondence: [email protected] (M.Z.); [email protected] (Y.Z.) Received: 30 November 2019; Accepted: 14 January 2020; Published: 16 January 2020 Simple Summary: Anaerobic rumen fungi play a vital role in fiber degradation. The objective of this study was to compare the anaerobic rumen fungal communities of full grazing ruminants in the Qinghai-Tibetan Plateau. Our results showed that the anaerobic rumen fungal community was affected by host species and the dynamic associations of them were host specific. This is the first study exploring the anaerobic rumen fungi in the full-grazing ruminants, which could lay a solid foundation to really identify fiber degradation fungal taxa using culture-dependent techniques in the future.
    [Show full text]
  • Optimizing Ruminal Fermentation with Organic Acids
    Optimizing Ruminal Fermentation with Organic Acids Scott A. Martin Department of Animal and Dairy Science The University of Georgia, Athens 30602-2771 Introduction Only some strains of S. ruminantium (subspecies lactilytica) are able to ferment lactate (Stewart and Much interest has been generated over the Bryant, 1988). past few years aimed at evaluating alternative means to manipulate the gastrointestinal microflora in production Early research showed that S. ruminantium livestock. Motivation for examining these alternatives HD4 requires L-aspartate, CO2, p-aminobenzoic acid, comes from increasing public scrutiny about the use of and biotin for growth in a lactate-salts medium antibiotics in the animal feed industry. However, (Linehan et al., 1978). In addition, the requirement for compared to the amount of information available L-aspartate can be replaced by L-malate or fumarate. detailing the effects of antimicrobial compounds on Because little work had been done in this area since the ruminal fermentation, little research has been conducted report by Linehan et al. (1978), my laboratory initiated to evaluate alternatives to antimicrobial compounds. In studies to evaluate the effects of aspartate, fumarate, the past 10 yr, interest has increased in direct-fed and malate on growth and lactate uptake by S. microbial (DFM) products and research has been ruminantium HD4 (Nisbet and Martin, 1990). Growth conducted to examine the effects of DFM on ruminant of S. ruminantium HD4 in medium that contained DL- performance. While some of these products have lactate was stimulated approximately two-fold by 10 shown promise in favorably altering the ruminal mM L-aspartate, fumarate, or L-malate after 24 h of fermentation and improving animal performance, the incubation (Nisbet and Martin, 1990).
    [Show full text]
  • The Reticulo-Rumen
    The Reticulo-Rumen CATTLE, sheep, goats, camels, reindeer, and buffalo are ruminants. Their digestive systems include four-compartment stomachs. The largest is the rumen, from which the term "ruminant" is derived. The other compartments are the reticulum, omasum, and aboma- sum. The reticulum and rumen are referred to as the reticulo- rumen. Ruminants can convert coarse, fibrous feedstuffs, unsuitcd for simple-stomach animals, into meat, milk, fiber, and energy. Ru- minants can thrive on feeds that are high in fiber and deficient in essential amino acids and B vitamins because of their unique diges- tive system. The reticulo-rumen provides a suitable environment for the growth and development of bacteria that break down complex carbohydrates, change and synthesize proteins, synthesize vitamins of the B complex, and alter fats. The bacterial fermentation is carried out anterior to the true stomach (abomasum) and small intestine. This seems to be an efficient arrangement for the digestion and uti- lization of cellulose and provides for digestion of microbial products in the true stomach. Most forage-consuming animals, such as horses and rabbits, have a reverse arrangement. The number of ruminai bacteria per milliliter (one-thousandth liter) of rumen contents seems to be about lo billion to lOO billion. There may be approximately i million protozoa per milliliter. The capacity of the rumen is in the range of 4 to 10 liters in adult sheep and 100 to 300 liters in adult cattle; the total number of ruminai micro-organisms in an animal therefore is phenomenal. A number of types of ruminai bacteria have been isolated and classified; among them are streptococci, lactobacilli, and selenomonads.
    [Show full text]
  • Rumen Fermentation and Fatty Acid Composition of Milk of Mid Lactating Dairy Cows Grazing Chicory and Ryegrass
    animals Article Rumen Fermentation and Fatty Acid Composition of Milk of Mid Lactating Dairy Cows Grazing Chicory and Ryegrass Mancoba Mangwe * , Racheal Bryant and Pablo Gregorini Faculty of Agriculture and Life Sciences, Lincoln University, P.O. Box 7647 Canterbury, New Zealand; [email protected] (R.B.); [email protected] (P.G.) * Correspondence: [email protected]; Tel.: +6-422-492-3443 Received: 8 December 2019; Accepted: 14 January 2020; Published: 19 January 2020 Simple Summary: Enhancing the concentration of individual fatty acids (FA) in milk has been, for a long time, a major aim for researchers because certain FAs are linked with several health benefits in humans as well as improving the processing quality of milk products. It is well documented that diet, management regime, and extent of biohydrogenation in the rumen are critical in determining the composition of FA in the milk of dairy cows. This study investigated the effects of including chicory into the traditional feeding regime of ryegrass/white clover, and time of its allocation on milk production, rumen fermentation, and FA composition of milk and rumen digesta of dairy cows. Our findings show that allocation of mature chicory herbage to dairy cows at 50% of their ration modified rumen fermentation and improved both milk yield and the FA profile of the milk. Allocating chicory herbage during the afternoon is a useful strategy that can translate to improved milk production and quality. These findings reflect not just the feasibility of including chicory as part of a feeding regime, but also the role of chicory in rumen fermentation and biohydrogenation.
    [Show full text]
  • Increased Conjugated Linoleic Acid (CLA) in Milk Fat of Grazing Cows Is Not Explained by More CLA Production in the Rumen Z
    Increased Conjugated Linoleic Acid (CLA) in Milk Fat of Grazing Cows is not Explained by More CLA Production in the Rumen Z. Wu, M.N. Lahlou, L.D. Satter, L. Massingill and M.W. Pariza Introduction of alfalfa silage, corn silage, and a concentrate portion containing primarily corn and soybean meal. The grain Grazing and feeding high-oil diets increase the supplement offered to the grazing cows was the same concentration in milk of conjugated linoleic acid as the concentrate contained in the TMR. The (CLA), a demonstrated anticarcinogen. The increase supplement was fed at the rate of 8.4 kg/day (DM), has been attributed to more production of CLA as an accounting for about 40% of the total feed intake. intermediate in biohydrogenation of linoleic acid Rumen contents, omasal contents, blood plasma, and (18:2(n-6)) in the rumen. This theory explains the milk were sampled during the last 7 days in each of the increase in milk CLA during oil feeding but cannot 21-day periods and analyzed for CLA concentrations. satisfactorily explain the increase during grazing, because formation of CLA (cis 9, trans 11 18:2) from Results and Discussion 18:2(n-6) is known but formation from 18:3(n-3) is unknown. The predominant fatty acid in pasture forage Fat content of milk did not differ between treatments, is linolenic acid (18:3(n-3)) (60 to 70%) rather than but the concentration of CLA in milk fat was 18:2(n-6) (5 to 20%). The objective of this study was approximately 50% higher (P < 0.05) during grazing to determine the relationship between production of than during TMR feeding (Table 1).
    [Show full text]